Added most recent version of unmodified HL2 SDK for Episode 1 engine

tier1/bitbuf.cpp

@@ -0,0 +1,960 @@
+//========= Copyright <20> 1996-2005, Valve Corporation, All rights reserved. ============//
+//
+// Purpose: 
+//
+// $NoKeywords: $
+//
+//=============================================================================//
+
+#include "bitbuf.h"
+#include "coordsize.h"
+#include "vector.h"
+#include "mathlib.h"
+#include "vstdlib/strtools.h"
+
+
+// FIXME: Can't use this until we get multithreaded allocations in tier0 working for tools
+// This is used by VVIS and fails to link
+// NOTE: This must be the last file included!!!
+//#include "tier0/memdbgon.h"
+
+#ifdef _XBOX
+// mandatory ... wary of above comment and isolating, tier0 is built as MT though
+#include "tier0/memdbgon.h"
+#endif
+
+static BitBufErrorHandler g_BitBufErrorHandler = 0;
+
+
+void InternalBitBufErrorHandler( BitBufErrorType errorType, const char *pDebugName )
+{
+	if ( g_BitBufErrorHandler )
+		g_BitBufErrorHandler( errorType, pDebugName );
+}
+
+
+void SetBitBufErrorHandler( BitBufErrorHandler fn )
+{
+	g_BitBufErrorHandler = fn;
+}
+
+
+// #define BB_PROFILING
+
+
+// Precalculated bit masks for WriteUBitLong. Using these tables instead of 
+// doing the calculations gives a 33% speedup in WriteUBitLong.
+unsigned long g_BitWriteMasks[32][33];
+
+// (1 << i) - 1
+unsigned long g_ExtraMasks[32];
+
+class CBitWriteMasksInit
+{
+public:
+	CBitWriteMasksInit()
+	{
+		for( unsigned int startbit=0; startbit < 32; startbit++ )
+		{
+			for( unsigned int nBitsLeft=0; nBitsLeft < 33; nBitsLeft++ )
+			{
+				unsigned int endbit = startbit + nBitsLeft;
+				g_BitWriteMasks[startbit][nBitsLeft] = (1 << startbit) - 1;
+				if(endbit < 32)
+					g_BitWriteMasks[startbit][nBitsLeft] |= ~((1 << endbit) - 1);
+			}
+		}
+
+		for ( unsigned int maskBit=0; maskBit < 32; maskBit++ )
+			g_ExtraMasks[maskBit] = (1 << maskBit) - 1;
+	}
+};
+CBitWriteMasksInit g_BitWriteMasksInit;
+
+
+// ---------------------------------------------------------------------------------------- //
+// bf_write
+// ---------------------------------------------------------------------------------------- //
+
+bf_write::bf_write()
+{
+	m_pData = NULL;
+	m_nDataBytes = 0;
+	m_nDataBits = -1; // set to -1 so we generate overflow on any operation
+	m_iCurBit = 0;
+	m_bOverflow = false;
+	m_bAssertOnOverflow = true;
+	m_pDebugName = NULL;
+}
+
+bf_write::bf_write( const char *pDebugName, void *pData, int nBytes, int nBits )
+{
+	m_bAssertOnOverflow = true;
+	m_pDebugName = pDebugName;
+	StartWriting( pData, nBytes, 0, nBits );
+}
+
+bf_write::bf_write( void *pData, int nBytes, int nBits )
+{
+	m_bAssertOnOverflow = true;
+	StartWriting( pData, nBytes, 0, nBits );
+}
+
+void bf_write::StartWriting( void *pData, int nBytes, int iStartBit, int nBits )
+{
+	// Make sure it's dword aligned and padded.
+	Assert( (nBytes % 4) == 0 );
+	Assert(((unsigned long)pData & 3) == 0);
+
+	m_pData = (unsigned char*)pData;
+	m_nDataBytes = nBytes;
+
+	if ( nBits == -1 )
+	{
+		m_nDataBits = nBytes << 3;
+	}
+	else
+	{
+		Assert( nBits <= nBytes*8 );
+		m_nDataBits = nBits;
+	}
+
+	m_iCurBit = iStartBit;
+	m_bOverflow = false;
+}
+
+void bf_write::Reset()
+{
+	m_iCurBit = 0;
+	m_bOverflow = false;
+}
+
+
+void bf_write::SetAssertOnOverflow( bool bAssert )
+{
+	m_bAssertOnOverflow = bAssert;
+}
+
+
+const char* bf_write::GetDebugName()
+{
+	return m_pDebugName;
+}
+
+
+void bf_write::SetDebugName( const char *pDebugName )
+{
+	m_pDebugName = pDebugName;
+}
+
+
+void bf_write::SeekToBit( int bitPos )
+{
+	m_iCurBit = bitPos;
+}
+
+
+// Sign bit comes first
+void bf_write::WriteSBitLong( int data, int numbits )
+{
+	// Do we have a valid # of bits to encode with?
+	Assert( numbits >= 1 );
+
+	// Note: it does this wierdness here so it's bit-compatible with regular integer data in the buffer.
+	// (Some old code writes direct integers right into the buffer).
+	if(data < 0)
+	{
+#ifdef _DEBUG
+	if( numbits < 32 )
+	{
+		// Make sure it doesn't overflow.
+
+		if( data < 0 )
+		{
+			Assert( data >= -(1 << (numbits-1)) );
+		}
+		else
+		{
+			Assert( data < (1 << (numbits-1)) );
+		}
+	}
+#endif
+
+		WriteUBitLong( (unsigned int)(0x80000000 + data), numbits - 1, false );
+		WriteOneBit( 1 );
+	}
+	else
+	{
+		WriteUBitLong((unsigned int)data, numbits - 1);
+		WriteOneBit( 0 );
+	}
+}
+
+// writes an unsigned integer with variable bit length
+void bf_write::WriteUBitVar( unsigned int data )
+{
+	unsigned int bits = 0;
+	unsigned int base = 0;
+
+	while (data > (base<<1))
+	{
+		bits++;
+		base = (1<<bits)-1;
+	}
+
+	// how many bits do we use
+	if ( bits > 0)
+		WriteUBitLong( 0, bits );
+
+	// end marker
+	WriteOneBit( 1 );  
+
+	// write the value
+	if ( bits > 0)
+		WriteUBitLong( data - base , bits );
+}
+
+void bf_write::WriteBitLong(unsigned int data, int numbits, bool bSigned)
+{
+	if(bSigned)
+		WriteSBitLong((int)data, numbits);
+	else
+		WriteUBitLong(data, numbits);
+}
+
+bool bf_write::WriteBits(const void *pInData, int nBits)
+{
+#if defined( BB_PROFILING )
+	VPROF( "bf_write::WriteBits" );
+#endif
+
+	unsigned char *pOut = (unsigned char*)pInData;
+	int nBitsLeft = nBits;
+
+	if((m_iCurBit+nBits) > m_nDataBits)
+	{
+		SetOverflowFlag();
+		CallErrorHandler( BITBUFERROR_BUFFER_OVERRUN, GetDebugName() );
+		return false;
+	}
+
+	// Get output dword-aligned.
+	while(((unsigned long)pOut & 3) != 0 && nBitsLeft >= 8)
+	{
+
+		WriteUBitLong( *pOut, 8, false );
+		++pOut;
+		nBitsLeft -= 8;
+	}
+	
+	// check if we can use fast memcpy if m_iCurBit is byte aligned
+	if ( (nBitsLeft >= 32) && (m_iCurBit & 7) == 0 )
+	{
+		int numbytes = (nBitsLeft >> 3); 
+		int numbits = numbytes << 3;
+		
+		// Bounds checking..
+		// TODO: May not need this check anymore
+		if((m_iCurBit+numbits) > m_nDataBits)
+		{
+			m_iCurBit = m_nDataBits;
+			SetOverflowFlag();
+			CallErrorHandler( BITBUFERROR_BUFFER_OVERRUN, GetDebugName() );
+			return false;
+		}
+		
+		Q_memcpy( m_pData+(m_iCurBit>>3), pOut, numbytes );
+		pOut += numbytes;
+		nBitsLeft -= numbits;
+		m_iCurBit += numbits;
+	}
+
+	// Read dwords.
+	while(nBitsLeft >= 32)
+	{
+		WriteUBitLong( *((unsigned long*)pOut), 32, false );
+		pOut += sizeof(unsigned long);
+		nBitsLeft -= 32;
+	}
+
+	// Read the remaining bytes.
+	while(nBitsLeft >= 8)
+	{
+		WriteUBitLong( *pOut, 8, false );
+		++pOut;
+		nBitsLeft -= 8;
+	}
+	
+	// Read the remaining bits.
+	if(nBitsLeft)
+	{
+		WriteUBitLong( *pOut, nBitsLeft, false );
+	}
+
+	return !IsOverflowed();
+}
+
+
+bool bf_write::WriteBitsFromBuffer( bf_read *pIn, int nBits )
+{
+	// This could be optimized a little by
+	while ( nBits > 32 )
+	{
+		WriteUBitLong( pIn->ReadUBitLong( 32 ), 32 );
+		nBits -= 32;
+	}
+
+	WriteUBitLong( pIn->ReadUBitLong( nBits ), nBits );
+	return !IsOverflowed() && !pIn->IsOverflowed();
+}
+
+
+void bf_write::WriteBitAngle( float fAngle, int numbits )
+{
+	int d;
+	unsigned int mask;
+	unsigned int shift;
+
+	shift = (1<<numbits);
+	mask = shift - 1;
+
+	d = (int)( (fAngle / 360.0) * shift );
+	d &= mask;
+
+	WriteUBitLong((unsigned int)d, numbits);
+}
+
+void bf_write::WriteBitCoord (const float f)
+{
+#if defined( BB_PROFILING )
+	VPROF( "bf_write::WriteBitCoord" );
+#endif
+	int		signbit = (f <= -COORD_RESOLUTION);
+	int		intval = (int)abs(f);
+	int		fractval = abs((int)(f*COORD_DENOMINATOR)) & (COORD_DENOMINATOR-1);
+
+
+	// Send the bit flags that indicate whether we have an integer part and/or a fraction part.
+	WriteOneBit( intval );
+	WriteOneBit( fractval );
+
+	if ( intval || fractval )
+	{
+		// Send the sign bit
+		WriteOneBit( signbit );
+
+		// Send the integer if we have one.
+		if ( intval )
+		{
+			// Adjust the integers from [1..MAX_COORD_VALUE] to [0..MAX_COORD_VALUE-1]
+			intval--;
+			WriteUBitLong( (unsigned int)intval, COORD_INTEGER_BITS );
+		}
+		
+		// Send the fraction if we have one
+		if ( fractval )
+		{
+			WriteUBitLong( (unsigned int)fractval, COORD_FRACTIONAL_BITS );
+		}
+	}
+}
+
+void bf_write::WriteBitFloat(float val)
+{
+	long intVal;
+
+	Assert(sizeof(long) == sizeof(float));
+	Assert(sizeof(float) == 4);
+
+	intVal = *((long*)&val);
+	WriteUBitLong( intVal, 32 );
+}
+
+void bf_write::WriteBitVec3Coord( const Vector& fa )
+{
+	int		xflag, yflag, zflag;
+
+	xflag = (fa[0] >= COORD_RESOLUTION) || (fa[0] <= -COORD_RESOLUTION);
+	yflag = (fa[1] >= COORD_RESOLUTION) || (fa[1] <= -COORD_RESOLUTION);
+	zflag = (fa[2] >= COORD_RESOLUTION) || (fa[2] <= -COORD_RESOLUTION);
+
+	WriteOneBit( xflag );
+	WriteOneBit( yflag );
+	WriteOneBit( zflag );
+
+	if ( xflag )
+		WriteBitCoord( fa[0] );
+	if ( yflag )
+		WriteBitCoord( fa[1] );
+	if ( zflag )
+		WriteBitCoord( fa[2] );
+}
+
+void bf_write::WriteBitNormal( float f )
+{
+	int	signbit = (f <= -NORMAL_RESOLUTION);
+
+	// NOTE: Since +/-1 are valid values for a normal, I'm going to encode that as all ones
+	unsigned int fractval = abs( (int)(f*NORMAL_DENOMINATOR) );
+
+	// clamp..
+	if (fractval > NORMAL_DENOMINATOR)
+		fractval = NORMAL_DENOMINATOR;
+
+	// Send the sign bit
+	WriteOneBit( signbit );
+
+	// Send the fractional component
+	WriteUBitLong( fractval, NORMAL_FRACTIONAL_BITS );
+}
+
+void bf_write::WriteBitVec3Normal( const Vector& fa )
+{
+	int		xflag, yflag;
+
+	xflag = (fa[0] >= NORMAL_RESOLUTION) || (fa[0] <= -NORMAL_RESOLUTION);
+	yflag = (fa[1] >= NORMAL_RESOLUTION) || (fa[1] <= -NORMAL_RESOLUTION);
+
+	WriteOneBit( xflag );
+	WriteOneBit( yflag );
+
+	if ( xflag )
+		WriteBitNormal( fa[0] );
+	if ( yflag )
+		WriteBitNormal( fa[1] );
+	
+	// Write z sign bit
+	int	signbit = (fa[2] <= -NORMAL_RESOLUTION);
+	WriteOneBit( signbit );
+}
+
+void bf_write::WriteBitAngles( const QAngle& fa )
+{
+	// FIXME:
+	Vector tmp( fa.x, fa.y, fa.z );
+	WriteBitVec3Coord( tmp );
+}
+
+void bf_write::WriteChar(int val)
+{
+	WriteSBitLong(val, sizeof(char) << 3);
+}
+
+void bf_write::WriteByte(int val)
+{
+	WriteUBitLong(val, sizeof(unsigned char) << 3);
+}
+
+void bf_write::WriteShort(int val)
+{
+	WriteSBitLong(val, sizeof(short) << 3);
+}
+
+void bf_write::WriteWord(int val)
+{
+	WriteUBitLong(val, sizeof(unsigned short) << 3);
+}
+
+void bf_write::WriteLong(long val)
+{
+	WriteSBitLong(val, sizeof(long) << 3);
+}
+
+void bf_write::WriteFloat(float val)
+{
+	WriteBits(&val, sizeof(val) << 3);
+}
+
+bool bf_write::WriteBytes( const void *pBuf, int nBytes )
+{
+	return WriteBits(pBuf, nBytes << 3);
+}
+
+bool bf_write::WriteString(const char *pStr)
+{
+	if(pStr)
+	{
+		do
+		{
+			WriteChar( *pStr );
+			++pStr;
+		} while( *(pStr-1) != 0 );
+	}
+	else
+	{
+		WriteChar( 0 );
+	}
+
+	return !IsOverflowed();
+}
+
+// ---------------------------------------------------------------------------------------- //
+// bf_read
+// ---------------------------------------------------------------------------------------- //
+
+bf_read::bf_read()
+{
+	m_pData = NULL;
+	m_nDataBytes = 0;
+	m_nDataBits = -1; // set to -1 so we overflow on any operation
+	m_iCurBit = 0;
+	m_bOverflow = false;
+	m_bAssertOnOverflow = true;
+	m_pDebugName = NULL;
+}
+
+bf_read::bf_read( const void *pData, int nBytes, int nBits )
+{
+	m_bAssertOnOverflow = true;
+	StartReading( pData, nBytes, 0, nBits );
+}
+
+bf_read::bf_read( const char *pDebugName, const void *pData, int nBytes, int nBits )
+{
+	m_bAssertOnOverflow = true;
+	m_pDebugName = pDebugName;
+	StartReading( pData, nBytes, 0, nBits );
+}
+
+void bf_read::StartReading( const void *pData, int nBytes, int iStartBit, int nBits )
+{
+	// Make sure we're dword aligned.
+	Assert(((unsigned long)pData & 3) == 0);
+
+	m_pData = (unsigned char*)pData;
+	m_nDataBytes = nBytes;
+
+	if ( nBits == -1 )
+	{
+		m_nDataBits = m_nDataBytes << 3;
+	}
+	else
+	{
+		Assert( nBits <= nBytes*8 );
+		m_nDataBits = nBits;
+	}
+
+	m_iCurBit = iStartBit;
+	m_bOverflow = false;
+}
+
+void bf_read::Reset()
+{
+	m_iCurBit = 0;
+	m_bOverflow = false;
+}
+
+void bf_read::SetAssertOnOverflow( bool bAssert )
+{
+	m_bAssertOnOverflow = bAssert;
+}
+
+const char* bf_read::GetDebugName()
+{
+	return m_pDebugName;
+}
+
+void bf_read::SetDebugName( const char *pName )
+{
+	m_pDebugName = pName;
+}
+
+unsigned int bf_read::CheckReadUBitLong(int numbits)
+{
+	// Ok, just read bits out.
+	int i, nBitValue;
+	unsigned int r = 0;
+
+	for(i=0; i < numbits; i++)
+	{
+		nBitValue = ReadOneBitNoCheck();
+		r |= nBitValue << i;
+	}
+	m_iCurBit -= numbits;
+	
+	return r;
+}
+
+bool bf_read::ReadBits(void *pOutData, int nBits)
+{
+#if defined( BB_PROFILING )
+	VPROF( "bf_write::ReadBits" );
+#endif
+
+	unsigned char *pOut = (unsigned char*)pOutData;
+	int nBitsLeft = nBits;
+
+	
+	// Get output dword-aligned.
+	while(((unsigned long)pOut & 3) != 0 && nBitsLeft >= 8)
+	{
+		*pOut = (unsigned char)ReadUBitLong(8);
+		++pOut;
+		nBitsLeft -= 8;
+	}
+
+	// Read dwords.
+	while(nBitsLeft >= 32)
+	{
+		*((unsigned long*)pOut) = ReadUBitLong(32);
+		pOut += sizeof(unsigned long);
+		nBitsLeft -= 32;
+	}
+
+	// Read the remaining bytes.
+	while(nBitsLeft >= 8)
+	{
+		*pOut = ReadUBitLong(8);
+		++pOut;
+		nBitsLeft -= 8;
+	}
+	
+	// Read the remaining bits.
+	if(nBitsLeft)
+	{
+		*pOut = ReadUBitLong(nBitsLeft);
+	}
+
+	return !IsOverflowed();
+}
+
+float bf_read::ReadBitAngle( int numbits )
+{
+	float fReturn;
+	int i;
+	float shift;
+
+	shift = (float)( 1 << numbits );
+
+	i = ReadUBitLong( numbits );
+	fReturn = (float)i * (360.0 / shift);
+
+	return fReturn;
+}
+
+unsigned int bf_read::PeekUBitLong( int numbits )
+{
+	unsigned int r;
+	int i, nBitValue;
+#ifdef BIT_VERBOSE
+	int nShifts = numbits;
+#endif
+
+	bf_read savebf;
+
+	savebf = *this;  // Save current state info
+
+	r = 0;
+	for(i=0; i < numbits; i++)
+	{
+		nBitValue = ReadOneBit();
+
+		// Append to current stream
+		if ( nBitValue )
+		{
+			r |= 1 << i;
+		}
+	}
+	
+	*this = savebf;
+
+#ifdef BIT_VERBOSE
+	Con_Printf( "PeekBitLong:  %i %i\n", nShifts, (unsigned int)r );
+#endif
+
+	return r;
+}
+
+// Append numbits least significant bits from data to the current bit stream
+int bf_read::ReadSBitLong( int numbits )
+{
+	int r, sign;
+
+	r = ReadUBitLong(numbits - 1);
+
+	// Note: it does this wierdness here so it's bit-compatible with regular integer data in the buffer.
+	// (Some old code writes direct integers right into the buffer).
+	sign = ReadOneBit();
+	if(sign)
+		r = -((1 << (numbits-1)) - r);
+
+	return r;
+}
+
+unsigned int bf_read::ReadUBitVar()
+{
+	int bits = 0; // how many bits are used to encode delta offset
+
+		// how many bits do we use
+	while ( ReadOneBit() == 0 )
+		bits++;
+
+	unsigned int data = (1<<bits)-1;
+	
+	// read the value
+	if ( bits > 0)
+		data += ReadUBitLong( bits );
+
+	return data;
+}
+
+
+unsigned int bf_read::ReadBitLong(int numbits, bool bSigned)
+{
+	if(bSigned)
+		return (unsigned int)ReadSBitLong(numbits);
+	else
+		return ReadUBitLong(numbits);
+}
+
+
+// Basic Coordinate Routines (these contain bit-field size AND fixed point scaling constants)
+float bf_read::ReadBitCoord (void)
+{
+#if defined( BB_PROFILING )
+	VPROF( "bf_write::ReadBitCoord" );
+#endif
+	int		intval=0,fractval=0,signbit=0;
+	float	value = 0.0;
+
+
+	// Read the required integer and fraction flags
+	intval = ReadOneBit();
+	fractval = ReadOneBit();
+
+	// If we got either parse them, otherwise it's a zero.
+	if ( intval || fractval )
+	{
+		// Read the sign bit
+		signbit = ReadOneBit();
+
+		// If there's an integer, read it in
+		if ( intval )
+		{
+			// Adjust the integers from [0..MAX_COORD_VALUE-1] to [1..MAX_COORD_VALUE]
+			intval = ReadUBitLong( COORD_INTEGER_BITS ) + 1;
+		}
+
+		// If there's a fraction, read it in
+		if ( fractval )
+		{
+			fractval = ReadUBitLong( COORD_FRACTIONAL_BITS );
+		}
+
+		// Calculate the correct floating point value
+		value = intval + ((float)fractval * COORD_RESOLUTION);
+
+		// Fixup the sign if negative.
+		if ( signbit )
+			value = -value;
+	}
+
+	return value;
+}
+
+void bf_read::ReadBitVec3Coord( Vector& fa )
+{
+	int		xflag, yflag, zflag;
+
+	// This vector must be initialized! Otherwise, If any of the flags aren't set, 
+	// the corresponding component will not be read and will be stack garbage.
+	fa.Init( 0, 0, 0 );
+
+	xflag = ReadOneBit();
+	yflag = ReadOneBit(); 
+	zflag = ReadOneBit();
+
+	if ( xflag )
+		fa[0] = ReadBitCoord();
+	if ( yflag )
+		fa[1] = ReadBitCoord();
+	if ( zflag )
+		fa[2] = ReadBitCoord();
+}
+
+float bf_read::ReadBitNormal (void)
+{
+	// Read the sign bit
+	int	signbit = ReadOneBit();
+
+	// Read the fractional part
+	unsigned int fractval = ReadUBitLong( NORMAL_FRACTIONAL_BITS );
+
+	// Calculate the correct floating point value
+	float value = (float)fractval * NORMAL_RESOLUTION;
+
+	// Fixup the sign if negative.
+	if ( signbit )
+		value = -value;
+
+	return value;
+}
+
+void bf_read::ReadBitVec3Normal( Vector& fa )
+{
+	int xflag = ReadOneBit();
+	int yflag = ReadOneBit(); 
+
+	if (xflag)
+		fa[0] = ReadBitNormal();
+	else
+		fa[0] = 0.0f;
+
+	if (yflag)
+		fa[1] = ReadBitNormal();
+	else
+		fa[1] = 0.0f;
+
+	// The first two imply the third (but not its sign)
+	int znegative = ReadOneBit();
+
+	float fafafbfb = fa[0] * fa[0] + fa[1] * fa[1];
+	if (fafafbfb < 1.0f)
+		fa[2] = sqrt( 1.0f - fafafbfb );
+	else
+		fa[2] = 0.0f;
+
+	if (znegative)
+		fa[2] = -fa[2];
+}
+
+void bf_read::ReadBitAngles( QAngle& fa )
+{
+	Vector tmp;
+	ReadBitVec3Coord( tmp );
+	fa.Init( tmp.x, tmp.y, tmp.z );
+}
+
+int bf_read::ReadChar()
+{
+	return ReadSBitLong(sizeof(char) << 3);
+}
+
+int bf_read::ReadByte()
+{
+	return ReadUBitLong(sizeof(unsigned char) << 3);
+}
+
+int bf_read::ReadShort()
+{
+	return ReadSBitLong(sizeof(short) << 3);
+}
+
+int bf_read::ReadWord()
+{
+	return ReadUBitLong(sizeof(unsigned short) << 3);
+}
+
+long bf_read::ReadLong()
+{
+	return ReadSBitLong(sizeof(long) << 3);
+}
+
+float bf_read::ReadFloat()
+{
+	float ret;
+	Assert( sizeof(ret) == 4 );
+	ReadBits(&ret, 32);
+	return ret;
+}
+
+bool bf_read::ReadBytes(void *pOut, int nBytes)
+{
+	return ReadBits(pOut, nBytes << 3);
+}
+
+bool bf_read::ReadString( char *pStr, int maxLen, bool bLine, int *pOutNumChars )
+{
+	Assert( maxLen != 0 );
+
+	bool bTooSmall = false;
+	int iChar = 0;
+	while(1)
+	{
+		char val = ReadChar();
+		if ( val == 0 )
+			break;
+		else if ( bLine && val == '\n' )
+			break;
+
+		if ( iChar < (maxLen-1) )
+		{
+			pStr[iChar] = val;
+			++iChar;
+		}
+		else
+		{
+			bTooSmall = true;
+		}
+	}
+
+	// Make sure it's null-terminated.
+	Assert( iChar < maxLen );
+	pStr[iChar] = 0;
+
+	if ( pOutNumChars )
+		*pOutNumChars = iChar;
+
+	return !IsOverflowed() && !bTooSmall;
+}
+
+
+char* bf_read::ReadAndAllocateString( bool *pOverflow )
+{
+	char str[2048];
+	
+	int nChars;
+	bool bOverflow = !ReadString( str, sizeof( str ), false, &nChars );
+	if ( pOverflow )
+		*pOverflow = bOverflow;
+
+	// Now copy into the output and return it;
+	char *pRet = new char[ nChars + 1 ];
+	for ( int i=0; i <= nChars; i++ )
+		pRet[i] = str[i];
+
+	return pRet;
+}
+
+	
+bool bf_read::Seek(int iBit)
+{
+	if(iBit < 0)
+	{
+		SetOverflowFlag();
+		m_iCurBit = m_nDataBits;
+		return false;
+	}
+	else if(iBit > m_nDataBits)
+	{
+		SetOverflowFlag();
+		m_iCurBit = m_nDataBits;
+		return false;
+	}
+	else
+	{
+		m_iCurBit = iBit;
+		return true;
+	}
+}
+
+void bf_read::ExciseBits( int startbit, int bitstoremove )
+{
+	int endbit = startbit + bitstoremove;
+	int remaining_to_end = m_nDataBits - endbit;
+
+	bf_write temp;
+	temp.StartWriting( (void *)m_pData, m_nDataBits << 3, startbit );
+
+	Seek( endbit );
+
+	for ( int i = 0; i < remaining_to_end; i++ )
+	{
+		temp.WriteOneBit( ReadOneBit() );
+	}
+
+	Seek( startbit );
+	
+	m_nDataBits -= bitstoremove;
+	m_nDataBytes = m_nDataBits >> 3;
+}